Convert one column to standard date format in Python - python

For a date column I have data like this: 19.01.01, which means 2019-01-01. Is there a method to change the format from the former to the latter?
My idea is to add 20 to the start of date and replace . with -. Are there better ways to do that?
Thanks.

If format is YY.DD.MM use %y.%d.%m, if format is YY.MM.DD use %y.%m.%d in to_datetime:
df = pd.DataFrame({'date':['19.01.01','19.01.02']})
#YY.DD.MM
df['date'] = pd.to_datetime(df['date'], format='%y.%d.%m')
print (df)
date
0 2019-01-01
1 2019-02-01
#YY.MM.DD
df['date'] = pd.to_datetime(df['date'], format='%y.%m.%d')
print (df)
date
0 2019-01-01
1 2019-01-02

Related

How to remove hours, minutes, seconds and UTC offset from pandas date column? I'm running with streamlit and pandas

How to remove T00:00:00+05:30 after year, month and date values in pandas? I tried converting the column into datetime but also it's showing the same results, I'm using pandas in streamlit. I tried the below code
df['Date'] = pd.to_datetime(df['Date'])
The output is same as below :
Date
2019-07-01T00:00:00+05:30
2019-07-01T00:00:00+05:30
2019-07-02T00:00:00+05:30
2019-07-02T00:00:00+05:30
2019-07-02T00:00:00+05:30
2019-07-03T00:00:00+05:30
2019-07-03T00:00:00+05:30
2019-07-04T00:00:00+05:30
2019-07-04T00:00:00+05:30
2019-07-05T00:00:00+05:30
Can anyone help me how to remove T00:00:00+05:30 from the above rows?
If I understand correctly, you want to keep only the date part.
Convert date strings to datetime
df = pd.DataFrame(
columns={'date'},
data=["2019-07-01T02:00:00+05:30", "2019-07-02T01:00:00+05:30"]
)
date
0 2019-07-01T02:00:00+05:30
1 2019-07-02T01:00:00+05:30
2 2019-07-03T03:00:00+05:30
df['date'] = pd.to_datetime(df['date'])
date
0 2019-07-01 02:00:00+05:30
1 2019-07-02 01:00:00+05:30
Remove the timezone
df['datetime'] = df['datetime'].dt.tz_localize(None)
date
0 2019-07-01 02:00:00
1 2019-07-02 01:00:00
Keep the date only
df['date'] = df['date'].dt.date
0 2019-07-01
1 2019-07-02
Don't bother with apply to Python dates or string changes. The former will leave you with an object type column and the latter is slow. Just round to the day frequency using the library function.
>>> pd.Series([pd.Timestamp('2000-01-05 12:01')]).dt.round('D')
0 2000-01-06
dtype: datetime64[ns]
If you have a timezone aware timestamp, convert to UTC with no time zone then round:
>>> pd.Series([pd.Timestamp('2019-07-01T00:00:00+05:30')]).dt.tz_convert(None) \
.dt.round('D')
0 2019-07-01
dtype: datetime64[ns]
Pandas doesn't have a builtin conversion to datetime.date, but you could use .apply to achieve this if you want to have date objects instead of string:
import pandas as pd
import datetime
df = pd.DataFrame(
{"date": [
"2019-07-01T00:00:00+05:30",
"2019-07-01T00:00:00+05:30",
"2019-07-02T00:00:00+05:30",
"2019-07-02T00:00:00+05:30",
"2019-07-02T00:00:00+05:30",
"2019-07-03T00:00:00+05:30",
"2019-07-03T00:00:00+05:30",
"2019-07-04T00:00:00+05:30",
"2019-07-04T00:00:00+05:30",
"2019-07-05T00:00:00+05:30"]})
df["date"] = df["date"].apply(lambda x: datetime.datetime.fromisoformat(x).date())
print(df)

How to extract multiple parts of values of a single column?

I have a date column of the format YYYY-MM-DD. I want to slice the only year and month from it. But I don't want the "-" as I have to later convert it into an integer to feed into my linear regression model.
It's current datatype is "object".
Dataframe :-
date open close high low
0 2019-10-08 56.46 56.10 57.02 56.08
1 2019-10-09 56.76 56.76 56.95 56.41
2 2019-10-10 56.98 57.52 57.61 56.83
3 2019-10-11 58.24 59.05 59.41 58.08
4 2019-10-14 58.73 58.97 59.53 58.67
You can use pd.to_datetime to convert date column to datetime then use pd.Series.dt.strftime.
s = pd.to_datetime(df['date'])
df['date'] = s.dt.strftime("%Y%m") # would give 202010
# or
# df['date'] = s.dt.strftime("%y%m") # would give 2010
date --> your date column
df['date'] = pd.to_datetime(df['date'])
df['date'] = df['date'].apply(lambda x: x.strftime('%Y-%m'))

Cannot remove timestamp in datetime

I have this date column which the dtype: object and the format is 31-Mar-20. So i tried to turn it with datetime.strptime into datetime64[D] and with format of 2020-03-31 which somehow whatever i have tried it does not work, i have tried some methode from this and this. In some way, it does turn my column to datetime64 but it has timestamp in it and i don't want it. I need it to be datetime without timestamp and the format is 2020-03-31 This is my code
dates = [datetime.datetime.strptime(ts,'%d-%b-%y').strftime('%Y-%m-%d')
for ts in df['date']]
df['date']= pd.DataFrame({'date': dates})
df = df.sort_values(by=['date'])
This approach might work -
import pandas as pd
df = pd.DataFrame({'dates': ['20-Mar-2020', '21-Mar-2020', '22-Mar-2020']})
df
dates
0 20-Mar-2020
1 21-Mar-2020
2 22-Mar-2020
df['dates'] = pd.to_datetime(df['dates'], format='%d-%b-%Y').dt.date
df
dates
0 2020-03-20
1 2020-03-21
2 2020-03-22
df['date'] = pd.to_datetime(df['date'], format="%d-%b-%y")
This converts it to a datetime, when you look at df it displays values as 2020-03-31 like you want, however these are all datetime objects so if you extract one value with df['date'][0] then you see Timestamp('2020-03-31 00:00:00')
if you want to convert them into a date you can do
df['date'] = [df_datetime.date() for df_datetime in df['date'] ]
There is probably a better way of doing this step.

Pandas - Different time formats in the same column

I have a Dataframe that has dates stored in different formats in the same column as shown below:
date
1-10-2018
2-10-2018
3-Oct-2018
4-10-2018
Is there anyway I could make all of them to have the same format.
Use to_datetime with specify formats with errors='coerce' for replace not matched values to NaNs. Last combine_first for replace missing values by date2 Series.
date1 = pd.to_datetime(df['date'], format='%d-%m-%Y', errors='coerce')
date2 = pd.to_datetime(df['date'], format='%d-%b-%Y', errors='coerce')
df['date'] = date1.combine_first(date2)
print (df)
date
0 2018-10-01
1 2018-10-02
2 2018-10-03
3 2018-10-04

convert alphanumeric value to date

I get a1523245800 value in the date field from my incoming data feed. I wish to know, how to convert this value into the date dtype? I have tried pandas.to_datetime but that does not seem to work. thankyou.
here is my code
pd.to_datetime([`a1523245800`], errors='coerce')
and here is the output of the above:
DatetimeIndex(['NaT'], dtype='datetime64[ns]', freq=None)
Remove a by str[1:] for remove first char or str.extract for get numeric part first and then to_datetime with parameter unit:
df = pd.DataFrame({'date':['a1523245800','a1523245800']})
df['date1'] = pd.to_datetime(df['date'].str[1:], unit='s')
Or:
df['date1'] = pd.to_datetime(df['date'].str.extract('(\d+)', expand=False), unit='s')
print (df)
date date1
0 a1523245800 2018-04-09 03:50:00
1 a1523245800 2018-04-09 03:50:00

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